Re: Application logic and Business logic

From: Dmitry A. Kazakov (mailbox_at_dmitry-kazakov.de)
Date: 03/06/05 

Date: Sun, 6 Mar 2005 10:36:43 +0100

On Sat, 05 Mar 2005 21:23:06 +0100, Alfredo Novoa wrote:

> On Sat, 5 Mar 2005 16:34:30 +0100, "Dmitry A. Kazakov"
> <mailbox@dmitry-kazakov.de> wrote:
>
>>>>The very idea of DB is archaic.
>>>
>>> What a nonsense!
>>
>>Yes I meant exactly that. The idea of physical separation data from
>>application is archaic.
>
> But DBMS's are to logically separate data from applications!

What for?

> Who talked about physical separation?

Me

>>Is there data outside DB?
>
> Any set of data is a DB. Even sets of 1.

OK. Let's take this definition. Then anything that processes data is a
DBMS. For example: me writing: 1+1=2 is a DBMS. It is fine to me, but why
so much complaints about conventional programming then? We all are just
writing DBMS'es...
 
>>> An RDBMS must provide user ADT definition features.
>>
>>Excellent, maybe we mean just the same thing... But if I have advanced ADT
>>I need no DB.
>
> And what about relational operators,

I don't need them. 70% of types I am working with have no relational
operations defined on them. 20% have rather marginal use of it. 10% require
a substantial use in various containers.

> declarative constraint definition,

Good thing. I am extensively use constrained subtypes in Ada. Though it has
pitfalls (substitutability).

> declarative derivation rules, the security system,

Ah, that boring thing asking for user name and password upon connect? Very
impressive indeed. I saw nothing more elaborated than that. I saw no ADTs
with different protection levels interacting with other ADTs in different
safety rings. Anyway that should be OS business.

> the separation between the physical and the logical levels,

Are you talking about controlling HD heads?

> the automatic optimization,

God save us from that. I even don't use GC.

> the automatic physical database design,

It is pretty automatic, when you have no DB to design ...

> the centralization of the integrity rules,

Something tells me that centralization is a bad thing...

> the synchronization between different applications,

You mean blocking my and other applications while performing something that
otherwise would take 1ms?

> the metadata management, the transaction
> control, the backup and recovery control etc, etc?

Application backup?

>> DB is an implementation detail of ADT (of some presumably
>>persistent objects.)
>
> No, the ADT subsytem is a little part of a DBMS.
>
>>And what does "R" here? Why from the whole rich and
>>bright set of mathematical entities only "relation" deserves to be a
>>junction between things?
>
> Only "relation" is needed to manage data.

Incidentally only Sheffer stroke is needed. But I prefer a little more meat
to your vegetarian diet... 

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de